Orange-brown sulfur dye and process of making same.



UNITED STATES ATENT OFFICE.

ARTHUR WEINBERG AND OTTO LANGE, OF FRANKFORT-ON-THE-MAIN, GER- MANY, ASSIGNORS TO LEOPOLD OASSELLA 8; CO., OF FRANKFORT-ON- THE-MAIN, GERMANY.

ORANGE-BROWN SULFUR DYE AND PROCESS OF MAKING SAME.

SPECIFICATION. forming. part of Letters Patent No. 714,542, dated November 25, 1902. Application filed July 14, 1902. Serial No. 115,684. ($pecimens.)

obtained which is insoluble in dilute solutions of alkaline sulfids. To this end it is necessary to continue the heating until the evolution of any sulfureted hydrogen has entirely ceased. The product so obtained is insoluble in all solvents. If, however, it be heated for some time to about 120 centigrade, pref erably under pressure, together with a concentrated aqueous solution of alkaline sulfid or caustic alkali, it is transformed into a valuable sulfur color, dyeing unmordanted cotton from a bath containing alkaline sulfids orange-brown shades of absolute resistance to Washing, milling, and acids.

I The process is illustrated by the following example: Fifty kilos of metatoluylenediamin are introduced into onehundred and twenty five kilos sulfur previously melted in an iron vessel provided with stirrers.

As soon as the violent evolution of sulfureted hydrogen has ceased the melt is brought into a chamber which is ata temperature of about 250 centigrade and allowed to remain therein until it has formed a solid brittle mass and the smell of sulfureted hydrogen has disappeared. The

dium sulfid, previously brought to the melt.

A violent reaction takes place at about 110 to 120 centigrade. The vessel is then closed and the temperature kept at 120 centigrade until the mass has become completely soluble in water. The dyestuff is obtained by desiccation, or, preferably, separated by means of acids. It dyes unmordanted cotton orangebrown shades which are hardly changed by being treated with chromates. Peroxid of hydrogen turns them brighter. Thedyestufi is almost insoluble in concentrated sulfuric acid.

Having now described our invention and in what manner it may be carried out, what We claim is 1. The process of producing an orangebrown coloring-matter by heating metatoluyL enediamin with sulfur at a temperature exceeding 220 centigrade until an entirely insoluble product is obtained, and converting the thus-obtained substance into a soluble dyestuft' by heating it with alkaline substances substantially as described.

2. The orange-brown coloring-matter containing sulfur obtainable as hereinbefore described, soluble in water in the presence of alkaline sulfids with an orange-brown color, which solution on the addition of acids yields a brown precipitate almost insoluble in con centrated sulfuric acid, dyeing cotton orangebrown shades substantially as described.

Signed at Frankfort-on-the-Main, in the Province of Hesse-Nassau, Kingdom of Prussia, Germany, this 18th day of June, A. D.

ARTHUR WEINBERG. OTTO LANGE.

Witnesses:

JEA GRUND, CARL GRUND. 

